Our proposed continuation involves a further search for new photochemical transformations of synthetic utility, the further exploration of the chemistry of synthetic organic rods as enzyme-like models, the extension of uses of single photon counting as a tool for determining excited state behavior, and the study of mechanisms of electronically excited state reactions. In our continuation we plan to explore further the utility of our di-pi-methane rearrangement, to expand the generality of the vinylcyclopropene rearrangement (giving cyclopentadienes) we have uncovered, to complete our cyclohexadienone studies, to pursue the photochemistry of vinylcyclopentadienes and to continue our studies on allylcyclopropenes. Our efforts in organic photochemistry aim at a delineation of the factors governing excited state behavior and search for new photochemical reactions of utility to the synthetic and biochemist.